Cellulosic materials such as wood chips or bark mulch are commonly used as decorative mulches and ground covers to retain beneficial moisture and control weeds in planting beds. Such materials are aesthetically pleasing, are easily applied and maintained, and are inexpensive to produce. When dry, however, such materials are a fuel source for fire. As such, they can be a dangerous source of fire around buildings (and within buildings that contain interior planting beds).
Most cellulosic materials such as wood fiber and biomass have a natural tendency to resist flame or heat. They initially burn to a point that char (a carbon layer) is created on their outer surfaces. This process of partial combustion and development of a layer of carbon affords some level of resistance to flame and heat. A variety of methods and compositions have been developed to enhance the ability of certain materials to resist flame and heat.
For example, there have been attempts to increase the fire resistance of cellulosic material for use as decorative mulch and ground cover. U.S. Pat. No. 6,461,542 to Smith, et al, discloses a combination of cellulosic debris and asphalt-containing material. Such a combination, however, is more difficult to color than untreated cellulosic material and thus is not preferred as a decorative mulch. In addition, the asphalt component of the mixture will decompose more slowly than the cellulosic component, eventually leaving a ground cover composed only of asphalt-containing material.
Other fire-resistant compositions for cellulosic material, such as that disclosed in U.S. Pat. No. 6,652,633 to Pasek, et al., involve complicated preparation processes and overly complicated application processes to produce fire-resistant cellulosic material.
There remains a need for a simple, easy to apply resistant composition that can be applied to biomass, wood, and organic mulches to enhance such materials' ability to resist flame.
It is therefore an object of the present invention to provide a simple, easy to apply composition for biomass, wood and organic mulches, which increases their resistance to flame. It is also an object of the present invention to provide a simple easy to apply composition that treats such materials to increase their resistance to flame and provides a desirable decorative coloring. It is a further object of the present invention to provide a decorative mulch for landscape use that has fire-resistant properties and provides an aesthetically desirable coloring effect.